Reguarding the mayapple:
The mayapple is described as: a small plant, not reaching above 18 inches in height. It has one broad leaf at the top of an otherwise bare stalk (excepting the fruit, which grows up this stalk, and the occasional plant which branches into never more than two seperate leaves). The leaf is large, the stalk is attached to the center of the leaf. The leaf is lobed into five to seven seperate lobes. This entire plant is light green. It prefers the moist soils of bottom lands and ccan sometimes be found- in dense patches, higher on hillsides, in forested conditions. It rarely grows in fields or well lighted area, prefering shade. This plant begins growth as early as march in the south, april and may in more northerly area (hence the name MAY...). The plant produces a smallish, edible pod, however, this pod is sometimes hard to locate for upcoming reasons. The pod is light green to yellowish. It has a hard outer husk, and inside has some seeds in the center. The pod, to my mind, tastes like lemon waermellon cross- tart and "different" tasting. The pod is found, often, after the may apple leaves have wilted and turned yellow and brown not ripe when the plant is in leaved boom. The pod is located about half way up the stem. The best way to harvest these pods is to located and earmark patches of mayapples earlier in the year while they have the readily identifieable leaves. Later, after the leaves wilt out, one simply goes to the location and harvests the pods. (Hence the ...APPLE). This plant is refered to, in some areas as Mandrove, but is not to be confused with that very different plant.
I personally did not know the plant had medicinal properties, however that is not my general fort'e. I dont have a need for a laxative at the moment, but Ill keep it in mind=) .... DISCLAIMER: Pleease research any plant you think is edible, not by my description, but by several good books on the subject with pictures, to avoid mis identification. Mayapples are easy to ID, but as with anything new and potentially deadly (there are some deadly plants out there and it pays to research these along with edibles!) RESEARCH IT FIRST!

I doubt it's near extinction, I've seen forests carpeted with the
stuff. The leaves and unripe fruit are poisonous and fatal if
enough is eaten. The main use of the roots is to make podophyllin
resin for topical use on skin for removal of warts. It's still
prescribed by doctors. You should wear gloves when you're harvesting
the roots.

Taking it orally for a laxative isn't too safe. Yes it works but
only because you're poisoning yourself. I'm sure it's not good for
your liver.

The concentrations of podophyllotoxin in roots (sic) [rhizomes,
predominantly] is too minute to require gloves when harvesting. If
that were the case one should wear gloves when touching Juniper
(eastern red cedar) which also contains the podophyllotoxin and other
lignans. The plant morphology above is what you can read commonly but
it is not correct. The apical buds on last year's rhizomes
(underground stems) bear either the makings of a sexual shoot (one
that will flower) or a vegetative shoot (one that will produce only a
leaf). The vegetative shoot is composed of a single leaf consisting
of a petiole (the "stalk") and the blade (round and as above
described). A sexual shoot actually has a vertical stem that bears
two leaves, each with a short petiole and blade. The true stem and
the petioles have the same color, tissue, and texture - they look
alike. As they arisr from the stem, a "fork" is formed by the
petioles of these two leaves. A flower with its own little pedicle
will develop from the bottom (axis) of this "fork" (the bottom of the
fork being the apical meristem of the stem). The flower will produce
the fruit.

Outside of the historical treatment for warts and use as a laxative,
the compound podophyllotoxin is extracted from plant parts and used
to semi-synthesize imporant drugs used in the treatment of cancer.
These are etoposide, teniposide and I can't remember the third but
its the one still under patent. These drugs are, I understand, the
drugs of choice for testicular cancer and maybe small-cell lung
cancer. Although podophyllotoxin was originally isolated from
american Mayapple, and the drug development based on this, the source
for the podophyllotoxin is now a closely related species from India
and other spp. from China. I don't believe there is any market for
plant mateiral of the american species for production of these drugs.